Creation's easy: put a Date/Time field in the table (call it DateCreated) and
set its Default Value property to either =Date() to store the date, or
(probably better in most cases) to =Now() to store the date and time that the
record was created.
Tracking modifications is harder: table don't have usable events. you'll need
to take steps (using Access security say) to ensure that users can ONLY update
the table using a Form that you develop. In the Form's BeforeUpdate event set
a date/time field to Date() or to Now() as appropriate.
